Sixers sitting pretty for WBBL defence

The Sydney Sixers couldn't be better placed to defend their WBBL crown after entering this week's finals series in top spot on the back of five successive victories.

The Sixers (10-4) take on the fourth-placed Adelaide Strikers (8-6) at Adelaide Oval on Friday in mint form with Alyssa Healy back to her best following a devastating double (106 and 63) against the Strikers and opening partner Ellyse Perry the competition's leading run scorer (500).

The Sixers' other X-factor looms as comeback queen Sarah Coyte.

Her two match-winning bowling stints against Adelaide reaped 5-32 off eight overs in a stunning return to cricket after retiring last year to deal with anxiety issues.

"It's been a nice comeback," she said.

"The momentum we'll take from this weekend heading into the finals is definitely going to be beneficial.

"What a team - three finals spots in three years. Hopefully we can continue that."

The Sixers' semi-final opponent, Adelaide, faced a nervous wait as the fifth-ranked Brisbane Heat, attempting to displace them in the top four, went hard to boost their net run rate e playing the Sydney Thunder.

In the other semi-final, the second-ranked Sydney Thunder (10-4) tackle the third-placed Perth Scorchers (8-6) on Thursday at Optus Stadium in Perth with both teams coming off 1-1 weekend splits against the Heat and Renegades, respectively.

Thunder captain Alex Blackwell acknowledges her team hasn't fired with the bat lately but believes Sunday's clutch bowling will hold them in good stead.

"All our bowlers bowled under pressure," Blackwell said.

"It's a terrific experience leading into finals but we can work on our batting."

The Scorchers leapfrogged the Strikers on net rate into third spot with a win set up by fast bowler Katherine Brunt's stunning new ball spell.

Brunt captured 3-11 to take her WBBL wicket tally to a league-best 22 and ended the sixth-placed Renegades' finals hopes.

The Scorchers had two goals in mind - get the win, and do it quickly to ensure a superior net run rate than Adelaide and Brisbane.